Unfortunately - when you explain this to people there's no really good answer to their immediate "so what should I do?" question.
I no more "own" the bigiain.com domain than I own "bigiain" on HN, or "bigiain@gmail.com". While I can ensure I keep paying for it's registration, I have no doubt that if Monsanto or Goldman Sachs or Apple launched an new thing and trademarked it "Bigiain", my registrar would fold instantly to a legal demand from their lawyers, and I'd be just as out-in-the-cold as all those people without friends-of-friends in high enough places at Instafacetwigoo to "fix things", or with publicity platforms like @mat behind them.
I suspect in the future, there'll be a well known way to tie your online activity/reputation/network to a strong public key (with some distributed blockchain-like revocation/renewal audit trail). If anyone's working on something like that - I'd love to hear about it...